Maureen, do you then like Viscobond the most?

The thickness of Viscobond(most expensive) is only slightly more than Emerald(free with installation) but it is stain resistant and made of foam.

I am afraid too much thickness may cause uneven buckling or folds of the carpet later on. Viscobond is less dense than Emerald.

I'm not an expert, I only remember discussing with a friend who worked in the business. Not sure of a need for stain resistance for unpadding or the difference between foam and the other content...if you don't hear from others, maybe googling will help. We selected the second most expensive and it was quite thick, but we never had buckling (including on the stairs). We sold our home four years after so maybe this can happen, but I have a feeling buckling is due to poor installation.

You should always pair a quality carpet with a quality pad. If you are installing a builder grade carpet it is really a misnomer that the carpet will last longer pairing it with a better pad. The main reason a carpet will last is the fiber type and stats related to the fiber. A 6.6 nylon will out perform a polyester hands down. The viscobond is in part a urethane which will out perform the traditional re-bond pad. Good Luck to you!

My mother has had her carpet forever and she swears it's still is fine because she had commercial quality carpet pad installed underneath the carpet. So, I'm guessing quality carpet, quality pad equals longevity.

So, it seems like going with Viscobond is going to be a safer choice. Is that correct? It costs an extra $1000 compared to Emerald which is provided by the builder for free.

Thanks everyone!